Setting up profiles for
yourself or your clients on social media sites is an excellent idea.
First of all, it prevents someone else from creating a profile on the
social media site using your name. Second of all, it is great for
reputation management (more on that in a moment). Thirdly some social
media site profiles do actually pass PageRank, which you can choose to
pass back to your main site.

Social
media sites can be very effective in reputation management. Reputation
management comes into play when someone has said something negative
about you, and that negative comment is ranking highly in the search
results for your name, or your company’s name. It’s clearly not good
when this happens, but there is a way to at least partially address
this problem: create profiles for yourself on major social media sites.